The vascular endothelium constitutes a major organ that functions as a regulator of blood coagulation, inflammation and in the exchange of fluids and mediators between the intravascular compartment and parenchyma tissues. As such, the proper function of the endothelium is critical to overall homeostasis. A dysfunction of the endothelium resulting from an alteration in the expression of important surface molecules, can result in coagulation defects, local and systemic vascular inflammation, and enhancement in the progression and rupture of atherosclerotic plaque. These effects can further result in conditions including myocardial infarction, deep venous thrombosis, disseminated intravascular thrombosis, and stroke.
Certain cell surface proteins are altered in response to a vascular injury or insult, and can be used as markers of a dysfunctional endothelium. A critical class of such proteins is the receptors/ligands mediating cell-cell adhesion, including the integrins, selectins (e.g. ELAM) and members of the immunoglobulin superfamily such as ICAM and VCAM. These molecules are increased in response to a variety of stimuli including cytokines, and in addition to being important markers of a dysfunctional endothelium, play a key role in thrombotic, inflammatory and atherogenic processes in the vascular wall. Other activities, such as surface anticoagulant responses, are also impaired in states of endothelial dysfunction. A compound that could block endothelial dysfunction, as determined by measuring it ability to inhibit cell-cell adhesion or expression of procoagulant activities, could be useful in treating conditions such as sepsis, injuries involving major tissue damage and trauma, systemic inflammatory response syndrome, sepsis syndrome, septic shock and multiple organ dysfunction syndrome including DIC) as well as atherosclerotic plaque rupture and its associated sequela. Because cell-cell adhesion is a fundamental process of broad biological importance, the ability to specifically modulate adhesive proteins has the potential for many clinical applications outside of the vascular tissue including its use as an anti-inflammatory agent.